<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    :root {
      /* // 两个--开头 */
      --geek-color-primary: red;
      --color72: green;
    }

    /* 2 复用 */
    .list-item-active {
      /* color: var(--geek-color-primary); */
      color: var(--active-color);
    }

    .box2 {
      /* color: var(--geek-color-primary); */
      --active-color: #1677ff;
      color: var(--active-color);
    }
  </style>
</head>

<body>
  <div class="list-item-active">
    box
  </div>
  <hr />
  <div class="box2">box2</div>
</body>

</html>